The disclosure relates to an alkylation unit and process. Generally, alkylation is a process that can be used to produce a high quality, high octane gasoline from lower boiling feeds. Usually, commercial refinery plants alkylate a feed including an isoparaffin stream, typically including isobutane, and an olefin stream, typically including one or more C3-C5 olefins, to form branched chain paraffin products boiling in the gasoline range, which can include hydrocarbons boiling up to about 200° C.
Increasing capacity of an alkylation unit may be implemented by various methods. The problem with increasing the capacity of an alkylation unit is that simply increasing the flow of olefin lowers the isobutane/olefin ratio, which depresses the octane number of the alkylate product, which is an undesirable result.
Therefore, what is needed is an improved alkylation unit and process that maintain the desired isobutane/olefin ratio thereby minimizing octane loss.